Read Receipt / Create Task

Read Receipt in ZD2 Beta it was working for a day or so then just Vanished from the selection. In ZD2 (Build 10580) the update notes suggest there is a read receipt but it is not there? I have ZD2 on 2 Linux machines and 3 XP machines and all the same. This also happened with Tasks, you could right click an email and create a task and next thing it was gone? So is there a read receipt and if so how do I get it back